Warning! Spoilers ahead for Young Sheldon season 5.
George (Lance Barber) and Mary's (Zoe Perry) marital issues are more serious than perceived on Young Sheldon. It's no secret that Sheldon's (Jim Parsons) parents had a tumultuous relationship as both he and his mother often recalled on The Big Bang Theory. Young Sheldon has yet to explicitly tackle the couple's woes, often dancing around it to keep the sitcom's lightheartedness, but a recent detail in the spin-off suggests that their marriage is dangerously on the cusp of deteriorating.
Since George already died before the events of The Big Bang Theory, he never physically appeared on the sitcom unlike the rest of his family. But, he was very much a part of his son's narrative as Sheldon frequently shared stories about him. One thing was clear based on his anecdotes, however: George wasn't a good dad. This was supported by Mary (Laurie Metcalf), who never missed a chance to rag on her dead husband. So viewers were naturally surprised when Young Sheldon introduced a decent family man in George.
This is the biggest plot inconsistency between The Big Bang Theory and its prequel; at this point, it's unclear how CBS is planning to address the issue. But Young Sheldon appears to be setting up the fall of the Coopers' marriage, albeit gradually and subtly. Considering what has happened in the sitcom the last few episodes, it seemed like everything is back to normal for the couple following George's cheating scare and Mary's growing attraction to Youth Pastor Rob (Dan Byrd). But, that isn't the case. In fact, Young Sheldon season 5, episode 14 titled, "A Free Scratcher and Feminine Wiles," revealed that George has been quietly struggling in his marriage that he was even considering the idea of divorce — something he brought up while hanging out with his friend. This was after he got into an argument with Mary about what to do with their $500 lottery winnings.
George was pushing his wife to use the money for her enjoyment which implied that he's still desperately wanting to stay in his marriage. Despite multiple arguments between them in the last couple of seasons, not to mention his attraction to Brenda, George remains committed to his wife. This is why seeing Mary enjoying her time hanging out with Rob has really been weighing down on him. Despite this, he has yet to confront his wife about catching her smoking with her colleague. Granted that he has intentionally kept his borderline inappropriate dalliance with Brenda, at least it's clear that, ultimately, he wants to still be married to Mary. So the fact that he's starting to consider getting a divorce means that he's losing hope that they can salvage their relationship.
George's wife being oblivious to his internal turmoil makes their situation worse. Perhaps it would've been better if he just lays it out and talks openly about the real status of their relationship. But considering what's been established on The Big Bang Theory, unfortunately, Young Sheldon viewers can expect that the Coopers' marriage will only get worse moving forward.
Young Sheldon airs every Thursday on CBS.